import _thread
from time import sleep,ctime
def loop0():
	print('开始循环0次在：',ctime())
	sleep(4)
	print('结束循环0次在：',ctime())

def loop1():
	print('开始循环1次在：',ctime())
	sleep(2)
	print('结束循环1次在：',ctime())
def main():
	print('starting at:', ctime())
	_thread.start_new_thread(loop0, ())
	_thread.start_new_thread(loop1, ())
	sleep(6)
	print('all done at:', ctime())
	
if __name__ =='__main__':
	main()